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Topic Review (Newest First)

05-03-2014 02:50 PM

BuzzLOL

. That cam and Vortec heads should get you into the 350-400 HP range... did you find the noise yet? Loose rocker arms?

Double checked TDC, it's good. Will try and dig into more tomorrow to see what i find.

04-22-2014 11:25 AM

BuzzLOL

. Just today stumbled across this old thread with new postings/updates... I would have suggested the 200-4R tranny as someone else above did, since it's the same length as the PowerGlide and can use the same driveshaft... but, since you have the 700-R4 at a super deal, that will work as well and give an even lower 3.05:1 1st gear vs the 200-4R's 2.74:1 1st (and TH350/TH400 2.54 1st), so that gets the big Impala moving even better off the line with a 327"... although a rather large jump from 1st to 2nd, but still light years better than a PowerSlide... also, the 700 has less overdrive than a 200, so also fits the smaller 327" better...

. 327 can make good low RPM torque, although the torque curve characteristics aren't quite as favorable as a longer stroke engine, but you prolly won't notice any difference on the street... a good combo of heads, cam, compression ratio, engine quench is much more important...

. What cam, head gaskets, and pistons did you end up with? ... I'd suggest up to about a 219/229 cam for a Vortec headed 327" in a large '66 Impala aiming toward 400 HP/400 torque... 9.5:1 - 10.5:1 compression ratio... Some people above apparently didn't read or understand your Alex 'no mods for Vortec heads' link above...

. The noise? maybe a problem with the fuel pump pushrod? Rod bolts that didn't get properly tightened? An exhaust rocker arm stud broke creating combustion back into intake manifold/carb.? Bent pushrod? Vortec heads originally came with self-guiding pushrods, you can't mix the guide plates system with the self-guiding system parts in the same engine! They will fit each other for alignment.

. The AirGap intake is fine since you're in Pasadena, Cal. and not particularly concerned with cold weather/engine warmup...

04-20-2014 10:05 AM

Hogg

Quote:

Originally Posted by techinspector1

There's really not much to add to this thread that is over a year old, except to put in my two cents worth concerning max lift on stock L31 heads.

If a fellow is to use anything over 0.425" valve lift in these motors without mods, he's asking for trouble. Is there room to do it? Yes. Are you using up the safety margin? Yes. You don't put a motor together without some play (safety margin) between the bottom of the retainer and the top of the seal to account for an over-rev.

The stock cams that came on ALL 1996-2003 L31 Vortec 350's use a cam with lift specs of 0.412/0.428" 191/196░ on a 111║ LSA.
And all 1996-2013 marine Vortec 350 engines engines, which use the same L31 Vortec 350 heads are used with a 196║/206║ 0.431"/0.451" 109║LSA, with 1.5:1 rockers.
Then we have the Ramjet 350 crate engine which uses that same 196/206║ 0.431"/0.451" 109║LSA roller cam, but this time GMPP(now CPP) decided to use the 1.6:1 full roller rockers which now puts lift up at 0.460"/0.481".

STock equipement

Clearance when using Comp 787-16 retainers which are designed for Beehive springs and the GEN 1 and GEN 1E and GEN 2 valve stem diameters.

Suggested install of valve seals.

peace
Hog

04-20-2014 07:54 AM

73gremlin

You sure its in time?

04-20-2014 01:54 AM

jexrod

I finally separated the engine and tranny, found the flex plate in good order. Started the engine with no tranny or exhaust attached and sounds like the noise is coming from the engine.... Haven't been able to adjust the carb, car starts immediately but dies when I step on the throttle. I hooked up a test light and it looks like its about 12-14 btdc. Oil pressure at idle is around 52. Sounds like a very loud backfire, any ideas on what to look for?

04-02-2014 04:36 PM

jexrod

Thanks, I'll inspect this weekend... hopefully the damage is visible and I'll start the tear down.

03-31-2014 10:05 PM

techinspector1

Quote:

Originally Posted by jexrod

So I finally dropped in the engine and tranny, had a hard time getting the gas from the tank to the carb. After a fuel pump swap the car stayed on for less than 10 sec and this clanking noise started. It got dark soon after so I was unable to do any major investigating. Any ideas on what it could be? Car ran for about 2 minutes and I shut it down.

Cracked flexplate. Get a SFI approved plate. They're tougher than a stock piece.

03-31-2014 08:57 PM

jexrod

So I finally dropped in the engine and tranny, had a hard time getting the gas from the tank to the carb. After a fuel pump swap the car stayed on for less than 10 sec and this clanking noise started. It got dark soon after so I was unable to do any major investigating. Any ideas on what it could be? Car ran for about 2 minutes and I shut it down.

I dropped off the driveshaft yesterday to be cut. I ended up installing the 700. Pretty easy swap except for slight clearance issues on the tunnel. Servo was rubbing. I ended up using Autolite 103's for spark plugs. Had a difficult time sourcing u joints (the zone, p boys) stores had a larger u joint specified in their system. The drive shop will source the right ones. Just installed the TCI lock up kit inside the pan, now trying to figure out how to wire the external harness. Any feedback on how to install the included vacuum switch? Ideally after much research I would like for it to unlock with the foot brake and vacuum switch?

03-20-2014 08:55 PM

dwwl

I would have to agree, that 66 impala is a heavy weight. Then you got the glide tranny. No matter how many ponies you get from the 327 cubes, that light weight nova even with 275 horses, will walk away from you. If you put a 350 tranny in that thing, it will be like driving a different car. If you want it to really move out, Put 4.11 gears in rear with a 700-r4 or 200 4r tranny and you'll have lower gears for street use and highway gears for the open road. Just a old guys opinion. Which those overdrives autos would of been around thirty years sooner. Got 355 cubes-200 4r tranny- 3.73 poss rear. what a mover.

03-19-2014 09:37 PM

jexrod

Forgot to mention I'm using headers, thanks for the feedback.

03-19-2014 03:50 PM

ap72

Quote:

Originally Posted by jexrod

Any suggestion on spark plugs? Do I look for a vortec engine plug or a 327 plug? gap? Thanks for the help trying to gather everything for this weekend. I'm using a generic HEI distributor.

a set of cheap copper replacement plugs for a 98 5.7L 1500 (stock vortec heads) will work just fine while you put the rest of the car together and tune it up. You can swap them after that or just keep using them, for most street driving they'll likely work just fine.

03-19-2014 03:50 PM

AutoGear

vortec plug

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